“…Considering the dark soliton solution u B.5 of (1), we can see that it describes the chirped dark soliton pulse for (1) 2 , and c 4 = a 4 2 , then the solutions ψ 13 , ψ 13 , ψ 22 , ψ 22 , ψ 33 , and ψ 33 in [4] are exactly the same as those obtained in this paper, named u A.1.1 , u B.5 , u A.4 , u B.6 , u A.8 , and u C.3 , respectively. In fact, the exact solutions u A.1.1 to u A.10 of (1), which are expressed by the single Jacobi elliptic function, can all be obtained in [4] with the above condition and in [16] …”